Recent research progresses of Sn/Bi/In-based electrocatalysts for electroreduction CO 2 to formate.

Carbon dioxide electroreduction reaction (CO 2 RR) can take full advantage of sustainable power to reduce the continuously increasing carbon emissions. Recycling CO 2 to produce formic acid or formate is a technologically and economically viable route to accomplish CO 2 cyclic utilization. Developing efficient and cost-effective electrocatalysts with high selectivity towards formate is prioritized for the industrialized applications of CO 2 RR electrolysis. From the previous explored CO 2 RR catalysts, Sn, Bi and In based materials have drawn increasing attentions due to the high selectivity towards formate. However, there are still confronted with several challenges for the practical applications of these materials. Therefore, a rational design of the catalysts for formate is urgently needed for the target of industrialized applications. Herein, we comprehensively summarized the recent development in the advanced electrocatalysts for the CO 2 RR to formate. Firstly, the reaction mechanism of CO 2 RR is introduced. Then the preparation and design strategies of the highly active electrocatalysts are presented. Especially the innovative design mechanism in engineering materials for promoting catalytic performance, and the efforts on mechanistic exploration using in situ (ex situ) characterization techniques are reviewed. Subsequently, some perspectives and expectations are proposed about current challenges and future potentials in CO 2 RR research.